Hacking a Mac Magsafe Jack into a PC Ultrabook

zenbookAir

Something’s fishy about the above-pictured ultrabook: it’s an Asus Zenbook that [WarriorRocker] hacked to use a MagSafe power connector typically found on Macbooks. Most of us probably consider it standard procedure to poke around inside our desktop’s tower, but it takes some guts to radically alter such a shiny new ultrabook. It seems, however, that the Zenbook’s tiny power plug causes serious frustrations, and [WarriorRocker] was tired of dealing with them.

Using information he found from an article we featured earlier this summer on a MagSafe teardown, [WarriorRocker] hit up the parts drawer for some connectors and got to work. He had to modify the MagSafe’s housing to fit his Zenbook while still holding on to the magnets, but he managed to avoid modifying the ultrabook’s case—the connector is approximately the same size as a USB port. Deciding he could live with just one USB connection, [WarriorRocker] took to the board with a pair of side cutters and neatly carved out space for the MagSafe next to the audio jack. He then soldered it in place and ran wires from the VCC and Ground pins along a the channel where the WiFi antenna is routed, connecting them to the original power jack’s input pins.

[WarriorRocker] regrets that he fell short of his original goal of getting the MagSafe’s protocol working: he instead had to hack on his own adapter. We’re still rather impressed with how well his hack turned out, and it did manage to solve the charging problems. Hit us up in the comments if you can provide some insight into the MagSafe’s otherwise obscure innerworkings.

Comments

  1. dext0rb says:

    Nice hardware hack for sure. How come you didn’t do anything with the 1-wire protocol though? It seems like that’s what’s needed for the adapter to give you the “full juice”.

    • The 1-wire protocol controls only the LED inside of the connector and nothing more. It is only used for status and does not send any information back to the adapter itself. The adapter will supply power regardless of the color or communication of the LED. Many long time macbook users will no doubt have encountered the “dim green light” on the magsafe connector that can happen when the center pin does not make good enough contact, the laptop still charges happily. I get the dim green light on my connector, likely this is due to a small amount of voltage spillover from the regulator or the chip inside.

      • matt says:

        Wikipedia says otherwise. Without the center pin, a MacBook Whatever will be powered but will not charge the batter. It also says it transmits the type of power adapter and the serial number of the power supply.

        • Paul says:

          You are correct matt, it would be more hazardous to always output the full potential is probably the cited reason.

          I know that this technique is used for safety in many batteries with controllers to prevent accidental shorting.

          • Regardless of what wikipedia says that facts are otherwise. The magsafe adapter will idle at a low voltage and amperage until it detects a certain magic load. The chip in the adapter tip simply reports to the macbook the wattage that it can support, again there is no communication between the tip of the adapter and the adapter itself.

      • Aqib says:

        You are wrong, there is a handshake between the SMC and the MagSafe adaptor. Via that single wire protocol.

        • Doug Penner says:

          As someone who has physically replaced the cable on a magsafe power adapter, I can tell you there are only *2* conductors that go from the brick to the laptop. An inner V+ line and an outter jacket that acts as ground. So unless they are communicating over the main power bus, the only thing the adapter could do is detect a specific load.

  2. matt says:

    Why would you want to do this? I can’t count how many MagSafe power adapters I’ve had fail due to inadequate strain relief.

    • Sasha says:

      They’re crazy convenient and not to hard to fix with a bit of hot glue and solder. Maybe not suitable for the average user, but I’m sure most HaD readers won’t mind.

      • matt says:

        The vast majority of mine have failed at the strain relief at the power jack. There isnt any easy way to open it up short of a hot xacto blade. I’m comfortable soldering but one of the major selling points of Apple products is their aesthetics. Having something wrapped in heat shrink tubing and epoxied together compromises this. And for what a used power adapter costs on eBay, anyone who can afford a MacBook Whatever would likely just buy another used adapter than perform a DIY fix. And I dont really see how MagSafe is any more convenient than a power adapter used on a PC laptop.

        • Jason says:

          I take it you’ve never struggled with the POS power connector on the Zenbooks. The thing falls out if you breathe on it, which prevents cord-tripping catastrophes. However, it’s so loose that the pin rocks around inside the jack and will lose contact even while fully inserted. It’s so bad that just the weight of the cord itself is enough to pull the power pin out of alignment.

          It’s infuriating to be working away thinking that your battery is charging, and then get hit with a low battery warning.

  3. Regulus says:

    That’s pretty awesome. I love those power connectors; strain relief issues aside, they’re way better than the stupid barrel-jack that most laptops I’ve seen use.
    I wish there was a non-apple version of this, but I don’t think I’ve seen it implemented outside the tablet/smartphone world.

  4. Indyaner says:

    Does anyone know for what I do have to google to find bulk magnetic connectors likes this one? I would love to use those for future projects but it seems that there is no actual product to buy sets of 10 like one can do with usb sockets/plugs (female/male).

    • Sasha says:

      I wanted to find some to in order to make my own cables, battery-powered chargers, etc. The cheapest I found was on Aliexpress, you had to buy the Magsafe car charger for ~$15. I haven’t found them separately.

      • Tony says:

        You could DIY; the concept is simple but it’s unlikely you could make something as nice as what Apple has.

        There’s a nice design over on Instructables, basically you chop a barrel connector in half, plug one end in to the device and add magnets to the rest. No device butchering needed.

        You can buy magnets with wires attached, the magnets are a bit large though. Making them isn’t that hard (magnets come in all sorts of sizes on eBay) but rare earth magnets don’t like heat, over 80 Celcius can damage them and soldering is 260C+.

        An alternative is to use copper tubing made for crimping wire or cord in jewellery making, but there’s only a few sizes. Solder wire to the tube, and then jam the magnet in.

        Then you’ve the hassle of making it spring loaded, reducing contact resistance (heat) etc. The Instructables article does mention the pitfalls.

        • Megol says:

          Eh… Apple haven’t really made anything new and making a “clone” isn’t that hard.
          Spring loaded connectors (a.k.a. pogo pins) + receptors + powerful magnets + hot glue = DIY magsafe.

          One just have to make sure that the magnets are powerful enough to ensure good contact pressure and that there are enough connectors to provide the required amperage. Last I looked at spring loaded connectors each connector was rated at ~2A so a normal 90W, 19.5V @ 4.7A notebook charger would conservatively need 3 connectors each for power and ground.

          Also when doing something like this there are a number of things that can be improved: e.g. the protection scheme used by Apple isn’t a good one. I’d recommend something like this instead:

          . the charger provides a short-circuit proofed low amperage, low voltage output on the power pins.
          . the computer/receptor have a microcontroller that is powered by this low output and begins sending a specific pulse pattern on a signal pin.
          . the charger detects this pattern and knows the connector is inserted correctly and enables the full output power.
          . if the signal pattern from the receptor stops the charger goes into detection mode again.

          The same scheme can of course be used to (like Apple) trigger charging LEDs and more. One example could be to provide intermediate modes for the charger so the computer can suck a little bit of power for e.g. charging something via USB even when sleeping and charged. Don’t know enough about computer switched supplies to know it it is useful in practice. :

          I’m planning to do a higher power version of the above with 9 contacts, 4 power, 4 ground and one signal wire. Some “art” below:

          MMM~o~MMM~o~MMM~o~MMM
          MMM~o~MMM~o~MMM~o~MMM
          MMM~o~MMM~o~MMM~o~MMM

          M = magnet
          ~o~ = a 3 pole spring loaded connector
          ~o~
          ~o~

          And connector layout:
          MMM~G~MMM~P~MMM~G~MMM
          MMM~P~MMM~S~MMM~P~MMM
          MMM~G~MMM~P~MMM~G~MMM

          G=ground, P=power, S=signal
          (sorry for the rant ;)

  5. fartface says:

    Apple has a superior design that other companies need to suck it up and license from them. Honestly, Asus could design their own but they choose to stick with the junky barrel connector, just like HP,Dell, etc…

    And why dont we have inductive charging for some of these things that ASUS is the same price as a macbook air, Asus should have put an inductive charger in it.

    • Greenaum says:

      I’d worry that the amount of power it needs to charge a laptop would interfere with hard drives, or whatever else. Lots of high-speed low-voltage circuits in a PC, and in a laptop they’re so squished together it’s really very impressive that they work so reliably. I think the risk of inducing unwanted currents all around the place is too high to use an inductive charger.

      Could be wrong but I don’t think there are any laptops that use inductive charging. It’s not really the miracle it’s made out to be. How big a deal is it to plug a plug in? For tiny things, weatherproof things, portable, low-power things, I suppose it’s useful, for the little Bluetooth trinkets and stuff.

      We could still do with a universal standard for DC power. USB’s de-facto standard isn’t bad but passing more than 2.5W uses ugly hacks. We could do with a simple alternative for decent amounts of power.

    • Marco says:

      That’s not how patents work … Apple doesn’t have to provide a license at a feasible cost and it almost certainly won’t to any company within it’s own market.

    • MegaMike says:

      What Apple did was take this connector design from deep-fat fryers and then patent use on laptops so no one else could do the same.

      This is barely innovation, and doesn’t seem inventive or non-obvious and yet the patent was granted so now no one else can use or develop the technology and Apple refuses to licence to others.

      Ref: http://en.wikipedia.org/wiki/MagSafe

    • matt says:

      Apple hates everyone else and thinks they suck. They refuse to license the patent and they’ll sue other companies who use these adapters even if they harvest them from offical Apple products:

      http://arstechnica.com/apple/2010/10/hypermac-to-halt-magsafe-sales-hopes-to-appease-apple/

    • Zac says:

      Because for an inductive charger, you need a big inductive mat, and you STILL run into problems with people tripping over the power cord.

  6. Sven says:

    Every time someone starts talking about how convenient the magsafe is, i dare them to go put their laptop on the workshop workbench among all the metal filings, just for a little while… I usually don’t get any more arguments after that except maybe a grumpy “that’s not what the Apple iWhatever was designed for!!”

    • matt says:

      To be fair, work environments such as that often use electronics with enclosures that have IP ratings. Assuming the filings are small enough, the fans in any laptop are likely to suck in fillings and short something out.

  7. mrx says:

    The big Question is WHY?
    Sure the IDEA is great, but in practice the magsafe connectors die so fast! I have had a Macbook Air for 2 years and I am on my third PSU.. They are so badly made and so expensive…

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